Method and system of welding with auto-determined startup parameters

Abstract

A method and system to determine optimum operating parameters for the startup phase of a welding-type process based on user-desired operating parameters of the post-startup or welding phase of the welding-type process are disclosed. While applicable to a number of welding-type processes, the method and system are particularly configured to determine an optimum wire feed speed for Gas Metal Arc Welding of aluminum using pulse spray transfer.

Description

BACKGROUND OF THE INVENTION [0001] The present invention is directed to welding and, more particularly, to a method and system of aluminum welding without preheating of a workpiece. The invention is particularly applicable with pulsed spray transfer welding. [0002] Gas Metal Arc Welding (GMAW), also referred to Metal Inert Gas (MIG) welding, combines the techniques and advantages of Tungsten Inert Gas (TIG) welding's inert gas shielding with a continuous, consumable wire electrode that is delivered to a weld by a wire feeder. An electrical arc is created between the continuous, consumable wire electrode and the workpiece. As such, the consumable wire functions as the electrode in the weld circuit as well as the source of filler metal. Gas Metal Arc Welding is a relatively simple process that allows an operator to concentrate on arc control. Gas Metal Arc Welding may be used to weld most commercial metals and alloys including steel, aluminum, and stainless steel. Moreover, the travel...

AI Technical Summary

Benefits of technology

[0009] A welding-type system is disclosed and includes a controller configured to determine optimum operating parameters for the startup phase of a welding-type process based on user-desired operating parameters of the post-startup or welding phase of the welding-type process. While applicable to a number of welding-type processes, the controller is particularly configured to determine an optimum wire feed speed for GMAW-P of alum...

Problems solved by technology

A drawback of GMAW-P with aluminum, however, is that customarily the workpiece to be weld must be preheated.

This undesirable weld joint is a result of the heat at the weld during start-up of the welding process being insufficient to melt the aluminum electrode and the workpiece into a molten pool.

That is, while aluminum has a relatively low melting point, aluminum also has a relatively low resistivity.

As can be appreciated, preheating adds to the time, cost, and complexity of the GMAW-P with aluminum process.

A drawback of this solution is that the initial or startup power levels are pre-set and thus independent of the user-defined parameters of the welding process.

For example, the proposed solution ignores the user-desired weld wire feed speed when setting the startup wire feed speed.

As a result, the abrupt changeover from the startup operating parameters to the post-startup parameters can negatively affect the quality of the weld.

Moreover, since the desired user parameters are not considered, the preset startup operating parameters may not be optimum for the given application.

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